Photographic print drier



Jan. 23, 1934.

J. s. GREENE .Pao'roGRAPmc'PRm'r DRIER Filed Jan. 28, 1931 INVENTOR ii;1S. .1 7'667I0 L215 .4 TTORNEY 50 24, 25, 26, 27, 28, 29, and 30.

Patented Jan. 23, 1934 UNITED STATES- PHOTOGRAPHIC PRINT DRIER John S.Greene, Rochester, N. Y., assignor to Photostat Corporation, Providence,R. 1., a corporation of Rhode Island Application January 28, 1931.Serial No. 511,818

7 Claims. (01. 34-4) This invention relates to a drier for use in dryingany material and particularly adapted for drying photographic prints.One object of the invention is the provision of a generally improved andmore satisfactory drier and one which will stand up well in service andrequire relatively little replacement.

Another object of the invention is to provide an improved drier belt ,sothat scorching or burn- 10 ing of the belt is substantially reduced orentirely eliminated.

A further object is the provision of a drier which will satisfactorilydry prints when run at temperatures materially lower than thetemperatures which'it has heretofore been necessary to use.

A still further object is the provision of a drier which will smooth oriron out prints better than has been done by prior constructions.

Another object of the invention is the provision of a simple andsatisfactory method of making drier belts.

To these and other ends the-invention resides in certain improvementsand combinations of parts, all as will be hereinafter more fullydescribed, the' novel features being pointed out in the claims at theend of the specification.

In the drawing:

Fig. 1 is a diagrammaticvertical section taken through a photographicprint drier constructed in accordance with a preferred embodiment of theinvention, and

Fig. 2 is an enlarged view of a fragment of the drier belt.

According to the present invention, the details of the drier except withregard to the belt may be of any usual or known construction. Forexample, the drier comprises a side frame 1Q on which is rotatablymounted a drum 11, and within the drum are spiders 12 mounted on an axle13, the spiders carrying mounting plates 14 between which electricheating elements 15 are secured to provide a source of heat for heatingthe drum 11.

4.45 An inner belt 20 encircles the drum 11 with one side thereof incontact with the drum, and is led over guide rollers 21 and 22 -asclearly shown in Fig. 1. An outer belt 23 also partially encircles thedrum and is led over guide rollers Suitable driving mechanism isprovided for rotating the drum 11 in a clockwise direction when viewedas in Fig. 1, and the driving mechanism may also be connected to part orall of the guide rollers over which the belts travel.

When the driving mechanism is operative, the belts move in the directionof the arrow 31, and a print deposited on the outer belt 23 at a. pointadjacent to arrow 31 will travel leftwardly toward the drum and will beembraced between the two 80 belts and carried around the heated drumuntil the belts separate again between the guide rollers 22 and 25, atwhich point the print will issue from between the belts as indicated bythe arrow 32. Both the inner and outer belts are preferably made offabric, such for example as canvas, so that they will absorb moisturefrom the prints and thus dry them more rapidly.

According to the present invention, the inner belt 21 is provided with ametallic coating on the face toward the drum, which metallic coating ispreferably in the form of finely divided particles of metal, such forexample as metallic paint. Preferably so-called aluminum paint is used,which is usually made from powdered aluminum bronze.

Fig. 2 shows on an enlarged scale a theoretical cross-section throughthe inner belt constructed according to the present invention. The baseor body of the belt, as shown at 20, is of a textile fabric such asheavy canvas or duck. The metallic coating is indicated at 35, and isintimately bonded with the fabric by partially filling the intersticestherein.

In applying the metallic paint to the fabric, 86 it is found thatimproved results are obtained if the paint be mixed with a thin oil of anonpenetrating, quick-drying character which will not permeate thefabric all the way through, but which will mainly remain on the side to90 which it is applied, so that the print in being dried does not comeinto contact with an oily surface. In actual use a satisfactory oil forthis purpose is found to be an oil readily obtainable on the commercialmarket under the trade name of Lionoil and made by Berry Brothers.

A mixture which is satisfactory in use consists of two tablespoonfuls ofaluminum bronze powder added to a pint of the above mentioned Lionoil,and thoroughly mixed. Preferably the mixture is applied tothe fabric bymeans of a spray gun, as when it is applied in this manner it permeatesand penetrates the fabric so that it becomes intimately and tenaciouslybonded therewith, although it does not pass through the fabric to theopposite side. Two coats are preferably used, the second coat beingapplied also by a spray gun after the first coat has dried.

It is found in actual practice that when the inner belt has had ametallic coating applied thereto as above disclosed, and particularly analuminum coating, remarkable and superior re sults are obtained. Thelife of the belt is greatly prolonged while at the same time the printsare dried in a more satisfactory manner.

It is desirable to build driers as small and compact as possible, andyet to have a large capacity. To obtain a large capacitywith arelatively small drum, a relatively high degree of heat must be used,and it has heretofore been customary to operate driers of this kind at atemperature of about 300 Fahrenheit. When a plain uncoated fabric beltis used in contact with the drier drum at such a temperature, the beltbecomes charred and burned so that its life is ordinarily only a fewweeks, after which it must be replaced.

When using a belt with a coating according to the present invention,however, it is found by actual tests and experiments that, using thesame temperatures, the life of the belt is materially longer and it doesnot char or burn to an extent necessitating replacement when used evenseveral times as long as it has been possible to use prior uncoatedbelts. Furthermore, it is found that the life of-the belt is furtherlengthened because it is possible to obtain equally satisfactory dryingof the prints by using a lower temperature of the drum.

For instance, whereas it has been necessary to use a temperature ofabout 300 Fahrenheit with uncoated belts, the drier will operatesatisfactorily at a temperature of only about 250 Fahrenheit when thebelt is coated in accordance with the present invention. This seems tobe. due to the fact that the metallic coating on the belt provides asmooth and even surface which makes a better contact with the drum thana plain fabric belt and the metal coating extending partially throughthe belt also serves to conduct the heat from the drum to and throughthe belt better than is done by a plain fabric belt, so that'the printis satisfactorily dried with a materially less temperature within thedrum.

Furthermore, the metallic coating 'of the present invention serves tostiffen the belt materially. While it does not prevent the belt frombending around the drum and the guide rollers, it does stiffen it tosuch a material extent that the belt smooths or irons out the printsbetter than a plain fabricbelt.

Thus the use of a belt coated according to the present inventionresults'ina more satisfactory drier which is economical because itrequires less heat than heretofore, and in which the belt need not bereplaced as often as heretofore. Furthermore, aside from the features ofeconomy, the work produced by such a drier is superior to the work doneby prior driers because of the better ironing or smoothing effectproduced by the improved belt.

While one embodiment of the invention has been disclosed, it is to beunderstood that the inventive idea may be carried out in a number ofways. This application is therefore not to be limited to the precisedetails described, but is intended to cover all variations andmodifications thereof falling within the spirit of the invention or thescope of the appended claims.

I claim:

1. Aphoto print drier comprising a source 0 heat and a belt movablerelative to said source of heat with one side of said belt toward saidsource, said belt having a coating of finely divided particles of metalincluding aluminum on the, side thereof toward said source of heat.

2. A photo print drier comprising a source of heat and a belt movablerelative to said source, said belt including a textile fabric having acoating of finely divided particles of metal on the side thereof towardsaid source of heat.

3. A photo print drier comprising a source of heat and a belt movablerelative to said source, said belt including a textile fabric having acoating .of metallic paint on one side thereof.

4. A photo print drier comprising a source of heat and a belt movablerelative to said source,

. said belt including a textile fabric having a coating'of metalintimately bonded with said fabric throughout substantially the entirearea thereof on the side thereof toward said source of heat.

5. A drier comprising a rotary drum, a source of heat within said drum,and a, belt partially encircling the drum with one side of the belt incontact therewith, said belt comprising a layer of fabric having a layerof metallic paint on the side thereof in contact with the drum.

6. A drier comprising a rotary drum, a source of heat within said drum,and a belt partially encircling the drum with one side of the belt incontact therewith, said belt comprising a layer of fabric having a layerof aluminum paint on the side thereof in contact with the drum.

7. A drier comprising a rotary drum, a source of heat within said drum,an inner belt partially encircling the drum with one side of the belt incontact therewith, and an outer belt partially encircling said drum andinner belt so that a print to be dried may be carried between said inner'and outer belts, said inner belt comprising a layer of fabric having acoating of metallic paint on the side thereof in contact with the drum,to reduce scorching of the'belt and to stiffen it to increase itssmoothing action on a print being dried.

JOHN S. GREENE.

